Last Sunday, at the ONE symposium in Johannesburg, you said: "This feels like the future." What did you mean?

We are all aware of our ancient pasts and this continent has a rich and extraordinary tradition. But the thing that excites me more is thinking about Africa's future – as the continent of the 21st century. It's one of the richest continents on Earth in terms of natural resources. If these resources are allowed to benefit the people above the ground, then they can pay for Africa's future.

Africa is also rich in terms of its human resources, with such a young, vibrant population. We have this image of Africans being the poorest people on Earth, but Africa itself is so rich. That is what makes the affront of poverty all the more stark. And sometimes we do have to raise the alarm and call the fire brigade, like when Aids is ripping through parts of Africa, but it's better if we can prevent the fire in the first place and build on the positives.

You listened to successive speakers talking about their ideas and the inspiration that was driving them. Then you said: "We have to change the story about Africa – or at least get out of the way of the real stories coming out of Africa." What do you mean?

It's about getting the balance right... a new entrepreneurial class here in Africa can find people like me irritating because we have tended to dramatise what is wrong with the continent to make things happen. But meanwhile they are making things happen and writing a new African story. Investment and private equity is booming in Africa. They're excited. I'm excited. Things are changing. Ory Okolloh, who spoke at the conference, said that there was a new train leaving the station in Africa – and that people in the west had better get on board or they'll miss out. This is the story, the train, that is coming out of Africa. We need to tell this story.

In terms of the story of Africa for the 21st century, we all need to be aware of the balance between growth and the remaining need for smarter aid.

Most people are saying that the 21st century will be China's. You say that it will be Africa's. Why?

Well, go talk to the Chinese. Why are they pumping so much investment into Africa? Why are they creating such a huge presence in Africa? They know where the future is. Ask them.

You know, these African lions are going to be a match for the Asian tigers. If the right economic plans are made and civic society can keep the vision honest, it will make our interest irrelevant. I never felt so good to feel so useless. These African lions will put us out of business.

I look at Mo Ibrahim and, although he might be an elder statesman, I see him as the new voice of Africa. People like him, they are drowning out our voices and so they should.

And so the future of aid in Africa is?

We mustn't forget that in general aid budgets are under threat, although thankfully not in the UK. And we mustn't forget that people's lives are dependent on it in the near term. And smart aid gets great results. A global alliance for vaccines has averted more than 5 million deaths this last decade and the Global Fund to Fight Aids, Tuberculosis and Malaria saves more than 4,000 lives a day. It's just about getting the balance right for the future and ensuring our smart aid today builds self-sustaining systems for the future .

And in terms of aid, let's remember the good stories that came out of debt cancellation and the Gleneagles promises. Let's not forget these success stories. In most cases, as verified by the World Bank, Africa's governments spent that money wisely and pulled millions of people out of poverty and despair. And that has helped destroy the mythology that money is wasted.

But we mustn't forget that there are concrete things we can do to speed Africa's path to the future, things that don't involve money. As part of the global grassroots Publish What You Pay coalition, ONE has lately been focusing on the extractive industries. We've seen the rush to extract oil, gas and minerals from poorer countries across the world. Our concern is how best to protect those countries and ensure citizens benefit. How to stop them going down the road of other countries suffering from the resource curse. How can you do that?

So the movement we're part of lobbied for an amendment to a finance bill in the US last year, to make legally sure that companies that are taking resources out of Africa have to disclose what they pay governments for the right to do that.

Now we're seeing leaders in Europe catching on, with Sarkozy telling me he'll push this at the EU. We're also looking for British leadership on this. Our mission is to make this a global requirement. So eventually there'll be no place to hide, and civil society groups will be able to challenge their government if the money they are making from the nations' resources isn't being used in the right way. Mo Ibrahim has said that this deal is bigger than debt cancellation for Africa. I'm proud to support the "publish what you pay" campaign that has been leading this issue for years.

There was a lot of talk at the ONE symposium about "transparency and technology" helping to change Africa. Are they?

You know, I think "transparency" is just a different way of saying "justice". And technology is helping people access this justice. That's what we've always been about. ONE is not an aid-giving charity, this is not even really about aid – it is about justice. It has always been about getting justice – that has always been the driving force.

And looking at what has happened in Cairo, it's clear that, in this new information age, people want justice. They don't just want to be heard, but they want to be able to hear as well. They want to know what is being done in their name. The direction of information technology, with more and more openness, is good for everyone.

You have been coming to Africa and working here over the past 20 years. You hadn't played South Africa since 1998. How did it feel?

Well, I said that it feels like the future. It was a big deal for me to be on that stage on Sunday night after working here on and off for 20 years. It is an incredible place. Many African cultures are a bit like the Irish – they enjoy and benefit from creative chaos being unleashed. The flexibility of Africa is a bonus for the sort of entrepreneurs and software kids who are creating the future. But don't listen to me – listen to their stories.